Sunday, 24 October 2010

Refurbishing a "Key WT 8 Amp No II"

I was lucky to be able to chat with Roy, w7el, and thank him for his excellent "Otpimized Transceiver" design, which has inspired - more or less directly - several of my homebrew efforts, including the VFO and Rx for the Funster Plus and the beacon receiver. Introducing Roy (who turns out to be a first-rate presenter), George g3rjv mentioned the Optimized Transceiver, rightly describing it as a "Classic".

I was also pleased to meet up again with another Roy, gm4vki, who was displaying his Russian Cold war era R354 "spy" transceiver. I was first to answer Roy's CQ after he'd got the R354 running earlier this month and I was using my replica Paraset - much joking about "spy to spy contacts" and ending the cold war!

Amidst all the other junk I collected to feed my kleptomania, I was pleased to find a 1941 "8 Amp" straight key going for a song (five quid actually). Fellow WARC member Jim, g3nfb, told me how he had "liberated" a similar key as a youngster - directly from a Lancaster!

I noticed that the key had a little damage - but it wasn't until I got it home that I realized the diecast yokes at either end of the key were cracked (I guess they used all the good metal on the Lancasters) ...

The bits had been put back together with superglue (which had made an insulating open circuit in the rear yoke with the result that even though the key felt nice, it didn't work as an electrical switch).

It has been a long time since I did much in the workshop (what with all the recent fun and games with the beacon) so I decided to spend some of today making some replacement parts to bring the key back to working order. I found some 1/2 inch thick alloy plate and hacked out a blank, which I squared up in my horizontal mill (itself a piece of history)...

I marked up for a couple of replacement "yokes" back-to back...

... and soon had them roughed out ...

After drilling and tapping the various holes, I filed the yokes to shape, trying to recreate something of the look of the cast originals. The result is seen below - I deliberately left the orange £5 price tag on for the camera so I can feel good about it!

Here's another view - it is mounted on a brass baseplate (which itself bears the marking "Key and Plug Assembly No 6" - no idea of the provenance of that component but it sounds "military").

I think it looks pretty authentic and - most importantly - it works again. Now perhaps I'll turn my attention to the pa0klt synth kit I got from Jan, g0bbl.

Vi suggerisco...

About Me

Engineer, who grew up in the age when hobbyists used a soldering iron (rather than a mouse) to mess with computers. Came late in life to amateur radio, where he operates the station m0xpd, conducts pointless experiments, and plays with words and ideas.